Factor Influencing The Shear Strength of Cohesionless Soil

The principal factors effecting the shearing strength of cohesion less soil are

1) Shape of particles

2) Gradation

3) Denseness

4) Confining pressure

5) Deviator stress

6) Intermediate principal stress

7) Loading

8) Vibration and repeated loading

9) Type of minerals

10) Capillary moisture

These parameters, stated above, are discussed below:

1) Shape of Particles

When other parameters is identical,angular shape particles of sand produce shear strength more than that of rounded shape particles.

2) Gradation

It is observed that a uniform graded sand have less shearing strength than that of well graded.

3) Denseness

When density increases interlocking increases to some extent. Consequently, the greater the denseness, the greater the strength.

Though the ultimate value of Ф′ is not affected by denseness, relative density(D_r) provides the value according to relation,

Ф′= 26^◦ +.2 D_r

4) Confining Pressure

Shear strength increases with an increase in confining pressure. But for the range of pressure in the common field problems, the effect of confining pressure on the angle of shearing resistance is not significance.